Immunological directives for biotherapy improvement in the treatment of colorectal cancer

Are immunological mechanisms involved in colon cancer and are they possible markers for biotherapy improvement?

This paper focuses on our data on colon cancer patients. Our overall results lead us to believe that the suppressive effect of specific cytokines in colon cancer patients alters the functionality of TH1 and TH2 subsets of CD4+ T-cells, with an expansion of TH2 cells and a malfunctioning of TH1 cells. This immunological disregulation appears to increase with stage progression, suggesting a direct role in the mechanisms that allow the tumour to locate and expand within the host. It is also clear that in order to identify disease markers and generate an in vivo immune response that corrects the imbalance between TH1 and TH2 cells, we need to understand how tumour mechanisms cause this imbalance to begin with.

Colon cancer and gene alterations: their immunological implications and suggestions for prognostic indices and improvements in biotherapy

Studies have shown that changes occur in c-Ki-ras, p53, and Bcl2 gene structure and function during the various stages of human colon carcinogenesis. Alterations of these genes are responsible for the establishment of a state of continuous stimulus for cell division and apoptotic inhibition at physiological and pharmacological levels. This paper focuses on the results of our research aimed at investigating how these gene alterations influence tumoral mechanisms on an immunological level and how immunological parameters can be used as prognostic markers for the passage of normal tissue to adenoma and adenoma to carcinoma. Overall, our data suggest that an alteration in the c-Ki-ras gene results in a switch to a suppressive type of immune response, determining an impairment of immune cell activation at both antigen- presenting-cell and T-cell levels. c-Ki-ras gene mutations, p53 deletions, and Bc12 expression, on the other hand, can be used as prognostic markers for the passage of normal tissue to adenoma and adenoma to carcinoma. The p53 oncogene does not appear to impair patients' immunological response further. In conclusion, an evaluation of c-Ki-ras, rather than p53 gene alterations, would seem to be more relevant in colon cancer prevention programs and biotherapy improvement.

The Study of a Patient's Immune System May Prove to be a Useful Noninvasive Tool for Stage Classification in Colon Cancer

Therapy, and, therefore, prognosis, is strictly related to cancer stage, and hence, screening tests that can contribute to the early classification of disease stage represent a step forward in treatment. Unfortunately, few prognostic indices are available, especially noninvasive ones. Our study of the physiological network of the immune response, however, leads us to believe that it may well be possible to define immunological indices for the classification of cancer stage using blood parameters. In this paper, we show how the study of a patient's immune system can be used as a noninvasive tool for early-stage classification.

Passage from normal mucosa to adenoma and colon cancer: alteration of normal sCD30 mechanisms regulating TH1/TH2 cell functions

The pathogenesis of cancer is currently under intensive investigation to identify reliable prognostic indices for the early detection of disease. Adenomas have been identified as precursors of colorectal cancer and tumor establishment, and disease progression has been found to reflect a malfunction of the immune system. On the basis of the role of the CD30 molecule in the regulation of TH1/TH2 functions and our previous results, strongly suggesting the validity of serum TH1/TH2 cytokines in the study of tumor progression, we studied network interaction between the production of soluble (s) CD30/sBCl2 in whole blood culture [in basic conditions and after PHA, LPS, and anti-CD3 monoclonal antibody (mAb) stimulation] and levels of TH1/TH2 cytokines (IL2, IFN gamma, IL12, IL4, IL5, IL10). Peripheral blood from a group of healthy subjects, as well as from patients with adenoma and colorectal cancer was used. Our objective was to gain a better insight into the role of the CD30 molecule in the passage from normal mucosa to adenoma and tumor and identify specific disease markers. Our results suggest that the decrease in CD30 expression and the abnormal increase in Bcl2 expression, observed in the peripheral cells of both adenoma and tumor groups determine an imbalance between TH1/TH2 functions. Consequently, changes in sCD30/sBcl2 culture production and TH1/TH2 cytokine serum levels may be reliable markers for tumor progression. In fact, our overall data show that a decrease of sCD30 levels in basic and PHA conditions and an increase of IFN gamma, IL4, IL5, and IL12 serum levels and sBcl2 in all activation condition are indicative of the passage from normal mucosa to adenoma; whilst a decrease of sBcl2 level in basic, LPS and anti-CD3 conditions and of IL2, IFN gamma serum levels, together with an increase of IL5 are indicative of the passage from adenoma to tumor.

Peripheral blood immunological parameters for use as markers of pre-invasive to invasive colorectal cancer

In cancer, the extent to which the disease has spread is probably the most important factor in determining patient prognosis. Hence practical and non-invasive methods are needed to identify disease stage. In a previous paper we showed how diagnostic and prognostic indices for disease progression could be defined by evaluating parameters in peripheral blood. The aim of this study was to identify further serum parameters that could be used. Serum levels of interferon (IFN) gamma, interleukin (IL)4, IL8, IL7, IL1 beta, tumor necrosis factor (TNF) alpha, granulocyte macrophage-colony stimulating factor (GM-CSF), soluble (s) IL2 receptor (R) and sIL6R were studied but only levels of IL4, sIL2R, IL8 and IL7 were found to be significant and would therefore be of use in defining diagnostic and prognostic indices for disease progression. In further detail, our results indicate that when serum levels of sIL2R < 522 U/ml, IL4 < 159 pg/ml and IL8 > 339 pg/ml there is a 95% probability that the disease is in stage I or II where there is no infiltration of lymph nodes; when serum levels of sIL2R > or = 522 Ug/ml, 159 pg/ml < or = IL4 < or = 319 pg/ml, and IL7 < 54 pg/ml, there is a 95% probability that the disease is in stage III and the tumor has invaded the lymph nodes; when the serum levels of IL4 > or = 431 pg/ml and IL7 > or = 54 pg/ml, there is a 95% probability that the disease is in stage IV and there is metastasis.

The role of the soluble CD30 serum level in colorectal cancer: a possible marker for a patient subset which could benefit from IL-2 biotherapy

On the basis of our previous data suggesting an impairment in host immune response in colorectal cancer caused by an inappropriate switch from TH1 towards TH2 cells, we investigated the role of the soluble CD30 (sCD30) in this disease, as this molecule was found related to immune responses characterized by the activation of a prevalence of TH2 cells. We studied a group of healthy subjects and colorectal cancer patients determining the sCD30 serum level and the following immunological parameters: s interleukin-2 receptor (sIL-2R), IL-2, interferon (IFN) gamma, IL-6, IL-4 and IL-10 levels in the serum and peripheral blood mononuclear cell (PBMC) production; PBMC proliferative responses to IL-2, anti-CD3 monoclonal antibody (CD3) and IL-2 + CD3. Our overall data indicate that in colorectal cancer the sCD30 serum level is also linked to a prevalence of the TH2 immune response activation. However, the Multivariate statistical study underlines that the sCD30 level is principally related to the IL-6 TH2 cytokine. Moreover, it suggests that in colorectal cancer, the sCD30 level might be a marker for identifying a patient subset in which IL-2 biotherapy treatment could contribute to the restoration of the impaired immune system.

IL-10 and sIL-2R serum levels as possible peripheral blood prognostic markers in the passage from adenoma to colorectal cancer

The pathogenesis of cancer is currently under intense investigation to identify reliable prognostic indices for the early detection of disease. Adenomas have been identified as precursors of colorectal cancer and tumor establishment, and disease progression has been found to reflect a malfunction of the immune system. We previously indicated the investigation of cytokine serum levels in these patients as a useful and non-invasive tool for the study of the disease progression and an imbalance at TH1 and TH2 cell levels was also found. Moreover, the soluble form of interleukin (IL) 2 receptor (sIL-2R) level is an in vivo marker of T cell activation and is used to monitor the activation of the immune system. We therefore performed an immunological study on a group of healthy subjects, subjects with adenomas, and colorectal cancer patients to identify peripheral blood invasiveness markers in the progression from normal mucosa through adenoma to tumor. In this paper we evaluated the relationships between serum levels of interleukin IL-2, sIL-2R, interferon (IFN) gamma, IL-4, IL-6, IL-10 and sICAM-1 and their networks. Our overall data indicate that in the normal mucosa through adenoma to tumor progression, the host immune response proceeded from a TH1 cell-mediated immune response type (healthy subjects) to a type with TH2 suppressive characteristics (adenoma subjects and cancer patients). However, in the adenoma subjects there was no IL-10 or sIL-2R involvement, while these parameters were implicated in the cancer patients' immune responses. Moreover, a concurrent augmentation of sIL-2R and IL-10 levels seems to be prognostic for the passage from adenoma to cancer, and the sIL-2R and sICAM-1 molecules appear to be involved in the invasiveness mechanisms.

The sCEA molecule suppressive role in NK and TH1 cell functions in colorectal cancer

The soluble form of carcinoembryonic antigen (sCEA), an oncofetal glycoprotein, is frequently produced by human epithelial-tumor cells, particularly of colorectal origin, and evaluated as a prognostic index of tumor progression and patient survival. sCEA molecules are often present at high concentrations in the peripheral blood of colorectal cancer patients, but the function and significance of this are not well understood. Reported data have demonstrated that sCEA can interfere in NK-cell/tumor-cell interaction by drastically reducing the lysis of tumor cells in a dose-dependent manner and can also suppress T and B cell functions. The aim of our study was to evaluate this situation in colorectal cancer by determining peripheral blood immunological parameters in a group of patients and healthy subjects. We evaluated the interleukin (IL)-2, interferon (IFN) gamma, IL-4, sIL-2R and IL-10 levels in the serum and the release of IFN gamma, IL-4 and IL-10 from peripheral blood mononuclear cells (PBMC); the PBMC expression of CD3, CD16 and CD19 phenotypic antigens; the PBMC proliferative responses to IL-2, IL-2 + anti-CD3 monoclonal antibody (mCD3) and mCD3. The statistical evaluation of our overall results strongly indicates that the high level of the sCEA molecules in the patient's serum might act as a suppressive factor for NK and TH1 immunocompetent cells. This may be the cause of sCEA involvement in tumor progression, and indicates the possibility of an improvement in cancer treatment through its manipulation.

Necessity of biotherapeutic treatments inducing TH1 cell functions in colorectal cancer

Our previous data on colorectal cancer suggest that there are faults at the level of mechanisms of the proliferative responses of patients peripheral blood mononuclear cells (PBMC) to the interleukin (IL)-2 and IL-2 PBMC production, which increase with the stage advancement. The damages in the proliferative response seem to be eliminated by the costimulator effects of the signals produced by the anti-CD3 monoclonal antibody (antiCD3), and the disregulation in TH subsets of CD4+ T cells with a malfunction of TH1 cells and an expansion of TH2, might contribute to this situation. So, by using biotherapeutic treatments to allow the generation of productive immune response in these patients it is essential to identify the defect in their immune system to discover how these mechanisms should be appropriately manipulated in vivo to switch their immune response from a non-productive to a productive one. We have studied this in a group of patients and healthy subjects as the control group, performing their immunological evaluation by determining these parameters: serum levels of IL-2, interferon (IFN) gamma, IL-4, IL-6, IL-7, IL-8, tumour necrosis factor (TNF) alpha, soluble IL-2 receptor (sIL-2R), intercellular adhesion molecule 1 (sICAM-1) and CD30 (sCD30) molecules; PBMC phenotypic antigens expression (CD3, CD4, CD8, CD19, CD16, CD56, CD57, CD25) on peripheral blood mononuclear cells (PBMC); proliferative response of PBMC to IL-2, IL-4 and anti-CD3 monoclonal antibody (antiCD3). Moreover, since mutant c-Ki-ras oncogene is a very frequent finding in colorectal cancers and there are indications which suggest its involvement in tumour progression, the analysis of c-ki-ras codon 12 and 13 were determined and the statistical evaluation of the above immunological parameters were performed by comparing the patient groups with (M+) and without (M-) these mutations with each other, and with the healthy group. The results underline the necessity of biotherapeutic treatments inducing TH1 cell functions in these patients. Moreover in M+ it seems also important to solve the problem of the switch from B to macrophage cells as immune cells which present antigens, and the possible involvement of c-Ki-ras gene mutations in the impairment of T cell receptor activation (TCR).

Prognostic significance of immunological evaluation in colorectal cancer

According to the concept that tumour establishment and progression generally reflects a malfunction of the immune system, we have investigated the prognostic significance of immunological parameters in correlation to stage progression in colorectal cancer. In patients and healthy subjects as control group, we determined: serum levels of interleukin (IL)-2, interferon (IFN) gamma, IL-4, IL-6, IL-7, IL-8, tumor necrosis factor (TNF) alpha cytokines and soluble IL-2 receptor (sIL-2R), CD30 (sCD30), ICAM-1 (sICAM-1) molecules, phenotype of peripheral blood mononuclear cells (PBMC); PBMC proliferative response to IL-2, IL-4 and anti-CD3 monoclonal antibody (anti-CD3) variously combined. Our results show that, compared to healthy controls, the group of all patients, but interestingly, also the groups of patients at the various stages of the disease, seem to have different values of these immunological parameters. Since tumour invasion and metastasis are the major causes of cancer treatment failure the early recognition of preinvasive states could lead to an improvement in prognosis. For this purpose our results might be especially useful in making prognostic and diagnostic indices in this neoplasy to identify patients at risk for tumour detention and the patient condition concerning disease progression by a non-invasive method. Moreover, this evaluation which contributes to identify the damage in the patient immune response to tumor could be helpful in identifying the therapeutic substances which might switch this response from being unproductive to productive. Thus, our data leads us to indicate that it might be possible to define reliable prognostic and diagnostic indices in colorectal cancer from the extension of this immunological study by the evaluation of these and other parameters.